TNF modulation is established as a new treatment modality for rheumatoid arthritis and Crohn""s Disease. TNF antagonists for the treatment of neurological disorders are the subject of two previous patents by the inventor. The present invention discloses new clinical data and concepts related to treating neurological damage associated with viral infection, epilepsy, and stroke.
Tumor necrosis factor (TNF) is intimately involved in the nervous system. It is central to the response to injury, either virally induced, or occurring as a result of mechanical trauma. TNF is also central to neuronal apoptosis, a process important in many neurological disorders.
TNF, a naturally occurring cytokine, plays a key role in the inflammatory response, in the immune response, and in the response to infection. TNF is formed by the cleavage of a precursor transmembrane protein, forming soluble molecules which aggregate in vivo to form trimolecular complexes. These complexes then bind to receptors found on a variety of cells. Binding produces an array of pro-inflammatory effects, including release of other pro-inflammatory cytokines, including IL-6, IL-8, and IL-1; release of matrix metalloproteinases; and up regulation of the expression of endothelial adhesion molecules, further amplifying the inflammatory and immune cascade by attracting leukocytes into extravascular tissues.
Specific inhibitors of TNF, only recently commercially available, now provide the possibility of therapeutic intervention in TNF mediated disorders. These antagonists, mainly developed to treat rheumatoid arthritis, include etanercept (Enbrel (R)xe2x80x94Immunex Corporation); infliximab (Rhemicade (R)xe2x80x94Johnson and Johnson); and D2E7, a human anti-TNF monoclonal antibody (Knoll Pharmaceuticals). These agents appear to be generally safe for chronic administration, and their efficacy for the treatment of rheumatoid arthritis has been established.
Few effective therapeutic agents are available for the treatment of neurological disorders. The nervous system has only a limited capacity for repair. Neurological injury is therefore often permanent, irreversible, and clinically devastating. There is an urgent need for effective treatments for a wide variety of neurological conditions, many of which are chronic, progressive, and incurable. TNF modulation with these new agents offers a new modality of treatment for many of these disorders.
Viral infections are associated with a wide variety of neurological disorders. These include Viral Meningitis, Viral Encephalitis, Postherpetic Neuralgia, HIV-associated Neurological Disorders (including HIV Dementia, HIV-associated Myelopathy, and HIV-associated Peripheral Neuropathy), HTLV-1 Myelopathy, Poliomyelitis, Influenza, Reye""s Syndrome, Meniere""s Disease, Trigeminal Neuralgia, and Herpes Zoster. Additionally, several neurological disorders of unknown etiology are probably the result of xe2x80x9ccryptogenicxe2x80x9d viral infection.
Neurological damage associated with viral infection can occur closely in association with the initial infection, or can, in other cases, follow after an extended interval. This damage occurring after a long interval can be associated with reactivation of a latent viral infection, as with herpes zoster, or through other mechanisms, not yet fully elucidated, such as in postpolio syndrome. Whether occurring acutely or after a long interval, TNF is centrally involved.
The response to viral infection causes immune system activation. Neurological damage associated with viral infection can be caused directly by viral invasion, or secondarily by immune activation. TNF modulation can limit this damage. TNF modulators can therefore be used to treat the above viral-associated disorders, either alone or in combination with antiviral therapy.
The object of the present invention is to provide clinical benefit to patients who have, or are at risk of experiencing a neurological disorder, through the use of a TNF modulator (the term modulator is used here synonymously with antagonist), either alone or in combination with an antiviral medication. TNF modulation in many of the disorders discussed will be effective as monotherapy. In the disorders discussed in which neurological damage occurs in association with active viral replication, such as with Herpes Zoster, or with Influenza infection, the use of additional antiviral therapy in combination with TNF modulation will provide additive, or even synergistic benefit. Monotherapy with the antiviral agents mentioned is not considered adequate therapy for any of the neurological conditions discussed. In some instances, monotherapy with a TNF antagonist will be effective, and the addition of an antiviral medication will produce added benefit. In other cases, TNF monotherapy will be ineffective, as will antiviral therapy by itself, but combination therapy will produce clinical improvement.
Combination therapy can be beneficial through several mechanisms, including the following:
1. Certain TNF modulators may be themselves directly viricidal or may directly inhibit viral growth or replication.
2. TNF may itself be a growth factor for certain viruses. TNF antagonism would, in these situations, function directly as an additional antiviral agent. This may be related to the research that has demonstrated that TNF is a growth factor for certain tumors, such as ovarian carcinoma.
3. In certain instances, TNF antagonism will have no direct effect on viral growth but will instead produce clinical improvement through direct modulation of the immune response which is associated with an active viral infection, or which was initiated by a preceding viral infection.
Pharmacologic chemical substances, compounds, and agents which are used for the treatment of neurological disorders, trauma, injuries, and compression having various organic structures and metabolic functions have been disclosed in the prior art. For example, U.S. Pat. Nos. 5,756,482 and 5,574,022 to Roberts et al disclose methods of attenuating physical damage to the nervous system and to the spinal cord after injury using steroid hormones or steroid precursors, such as pregnenolone and pregnenolone sulfate in conjunction with a non-steroidal anti-inflammatory substance, such as indomethacin. These prior art patents do not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body to treat the neurological disorders of the present invention.
U.S. Pat. No. 5,605,690 to Jacobs discloses a method for treating TNF-dependent inflammatory diseases, such as arthritis, by administering a TNF antagonist, such as soluble human TNFR (a sequence of amino acids), to a human. This prior art patent does not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body to treat the neurological disorders of the present invention.
U.S. Pat. No. 5,656,272 to Le et al discloses methods of treating TNF-alpha-mediated Crohn""s disease using chimeric anti-TNF antibodies. This prior art patent does not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body to treat the neurological disorders of the present invention.
U.S. Pat. No. 5,650,396 discloses a method of treating multiple sclerosis (MS) by blocking and inhibiting the action of TNF in a patient. This prior art patent does not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body to treat the neurological disorders of the present invention.
U.S. Pat. No. 6,093,819 to Hanson discusses the preparation of Famciclovir. This prior art patent does not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body or the use of Famciclovir or Acyclovir to treat the neurological disorders of the present invention.
U.S. Pat. No. 5,559,114 to Exley discloses the use of Acyclovir and Famciclovir at higher than normal doses to treat autoimmune disease. This prior art patent does not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body or the use of Famciclovir or Acyclovir to treat the neurological disorders of the present invention.
U.S. Pat. No. 4,199,574 to Schaefer discloses methods to treat viral infections. This prior art patent does not teach the use of the TNF modulators discussed herein for the suppression and inhibition of the action of TNF in the human body or the use of Famciclovir or Acyclovir to treat the neurological disorders of the present invention.
U.S. Pat. No. 5,866,581 to Boon discloses the use of Penciclovir and Famciclovir for the treatment or prophylaxis of Postherpetic Neuralgia. These drugs, however, are not effective for this use when used alone. This prior art patent does not teach the use of the combination of a TNF modulator together with Penciclovir or Famciclovir to treat the neurological disorders of the present invention. Such a combination is necessary to be effective in the treatment or prophylaxis of Postherpetic Neuralgia.
Accordingly, it is an object of the present invention to provide TNF modulation for treating neurological disorders associated with viral infection, including Postherpetic Neuralgia (PHN), Viral Meningitis, Viral Encephalitis, Poliomyelitis, HIV, HTLV-1 Myelopathy, Reye""s Syndrome, Meniere""s Disease, Trigeminal Neuralgia, Influenza, and Herpes Zoster.
It is a further object of the present invention to treat neurological disorders associated with viral infection with a combination therapy of TNF modulators and antiviral agents or antiretroviral agents. These disorders include PHN, Influenza, HIV, Herpes Zoster, and others.
It is a further object of the present invention to treat epileptic disorders with TNF modulators alone or with antiseizure drugs.
It is a further object of the present invention to treat stroke and cerebrovascular disease with TNF modulators.
It is a further object of the present invention to use TNF modulators as neuroprotective agents for patients who have had a previous stroke to limit future stroke damage, or for patients who have a cerebrovascular disease to limit the damage from future occlusive events.
The present invention provides a method for inhibiting the action of TNF for treating neurological conditions in a human by administering a TNF antagonist for reducing the inflammation of neuronal tissue of said human, or for modulating the immune response affecting neuronal tissue of said human, comprising the step of:
administering a therapeutically effective dosage level to said human of said TNF antagonist selected from the group consisting of etanercept, infliximab, and D2E7 (a human anti-TNF mAb from Knoll Pharmaceuticals) for reducing the inflammation of neuronal tissue of said human, or for modulating the immune response affecting neuronal tissue of said human.
In addition, for the viral-associated neurological disorders, the following additional step is performed:
administering a therapeutically effective dosage level to said human of an antiviral agent or anti-retroviral agents for reducing the inflammation of neuronal tissue of said human, or for modulating the immune response affecting neuronal tissue of said human.